I have a lemon tree at home that is in flower and the scent is
wonderful. While walking through a residential area I smelled something
similar. It turned out to be a clematis growing in someone's garden. I
noticed the same or a similar variety in other people's gardens.

I think that this must be Clematis armandii. It must be a common
variety. It has large leathery leaves and masses of small white
flowers. I have never grown a clematis before, so I would like to know
if this is a particular variety of C. armandii. I would also like to
know if there are any better types for scent than this. How would I
prune it?